The known flat-running devices usually consist of a supporting ring mounted with clearance around a wheel rim inside a tire casing. This ring, because of its width at its base, exerts a force pressing the casing onto the rim. Sometimes used are rigid devices in several sectors that are attached in twos. Thus, document EP-A-1 541 384 in the name of the Applicant presents a flat-running device for a mounted assembly with a rim with several portions of the bolted type comprising, on the one hand, a supporting ring of the hollow type designed to be mounted around the rim and divided into at least two ring sectors mounted independently of one another and, on the other hand, means for locking the beads of the casing against the rim edges that are designed to connect the ring sectors to these beads, for the purpose of ensuring the driving function of the mounted assembly in the event of reduced or zero pressure in the latter.
Document EP-A-233 547 also discloses a flat-running device for a multilock rim (i.e. not bolted) which is mounted on the rim by means of a flexible elastic shoe, the ribbed lateral edges of which are designed to press against the beads of the tire casing. In this device, the ring sectors are articulated together in twos by fitting into one another in the circumferential direction, via an axial pivot forming a hinge which passes right through the two sectors that it connects and on which these sectors can pivot.
A major drawback of the latter flat-running device with sectors articulated by hinges lies notably in the rigid character of these articulations because of the aforementioned fitment and hinge.
Document EP-A-1 588 870 presents an annular supporting structure with articulated ring sectors specifically for a one-piece wheel rim with circumferential well, the structure being able to be used without means for locking the beads against the rim edges. Each articulation between sectors consists of at least two link rods articulated on one another thus forming a complex deformable articulation with the two articulation holes in which the two transverse spindles are mounted that belong respectively to both link rods and not to only one and the same rigid lug, which notably has the drawback of making the articulations complex.